Seeking gastroenterologist advice. Well.

My father (57M) and mother(57F) have been taking Kayam tablets daily for over a year for constipation and are now completely dependent on them and cannot pass stool without them. Kayam contains 50% Senna and Mulethi (Licorice) which I understand can cause electrolyte imbalance and bowel dependency with long term use. My father had an abdominal USG done recently which also incidentally found a 4.2mm kidney stone in the left kidney (no hydronephrosis). He exercises daily and has no chest pain, palpitations or other symptoms. Looking for guidance from a gastroenterologist on: • Safe tapering plan to wean off Kayam • Whether Isabgol or Lactulose can help during transition • What blood tests should be done given this history • Whether the kidney stone needs treatment or just monitoring I am willing to follow up with additional appointments as well. Thanks!